[NsEditor] (Win32, freeware) NsEditor? for the Apocalyx Engine is a stand-alone script editor written to develop games for the Apocalyx engine. NsEditor? is written in Delphi. It's main target is to simplify Apocalyx game development by means of offering a rich set of features and a game framework. The most important editor features include:

NsEditor? is set up to also supports a complete game framework. The game framework is based on a set of prefab entities and macro functions. Entities are predefined code snippets, written as normal Lua functions, that can be insert into your personal game scripts.

Epsilon is an emacs-like editor that has been around for quite a few years in the DOS, OS/2, Windows, and lately Mac OSX and Linux platforms. A [simple Lua mode] is available, written in Epsilon's C-like extension language EEL. It is known to work with Epsilon 13, and probably works with some earlier versions as well. Save the liked file locally as luamode.e, compile to bytecode and load into the running Epsilon state with the compile-buffer command (which is probably bound to Alt+F3). Save the modified state file as usual (with the write-state command). The resulting major mode handles simple syntax highlighting and code indentation cases, but it does have blind spots and limitations.

[Eclipse] (open-source, EPL) is a Java IDE that can be extended to support Lua 5.1 with one of these plugins